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51.
Paul F.Smith Sameer M.Prabhu Jonathan H.Friedman 《电子设计应用》2008,(5):88-92
本文引入了基于模型设计的概念,突出了其中的一些优点,详细讨论了组织中采用基于模型设计文化的10个最佳策略。这些最佳策略从不同工业领域的公司中收集,包括向基于模型设计的成功或者不成功的过渡。 相似文献
52.
As cropland and pasture have replaced forest and cerrado in Brazilian Amazônia, concern has mounted over the effects of changing the biogeochemical and hydrological properties of one of the world's great storehouses of biomass and biodiversity. Although much recent effort has focused on the location, effects, and causes of deforestation and cerrado conversion, much less is known about the basin-wide spatial distribution and density of the land use following conversion for crops or pasture.In this paper, we use census and satellite records to develop maps of the distribution and abundance of major agricultural land uses across 4.5×108 ha of Brazilian Amazônia in 1980 and 1995. Results indicate an overall expansion of 7.0×106 ha in total agricultural area in Brazilian Amazônia between 1980 and 1995. The net change during this period is estimated for three different land-use types: croplands (an increase of 0.8×106 ha), natural pastures (a decrease of 8.4×106 ha), and planted pastures (an increase of 14.7×106 ha). These estimates, the first spatially explicit quantifications of agricultural land-use activities in 1980 and 1995 across Brazilian Amazônia, are shown to be consistent with the results of applying a land use change and secondary regrowth model to published deforestation rates for the period.The resulting time slices, presented for each land-use category at 5-min (∼9 km) spatial resolution, allow for the quantification of land-use changes in this region for biogeochemical, demographic and economic models. Several foci of agricultural change existed within Brazilian Amazônia during this period: in the state of Pará, cropland was lost and planted pasture increased markedly; in Mato Grosso, both cropland and planted pasture increased; in Rondônia, planted pasture replacing forest was the primary route to agricultural expansion. 相似文献
53.
Cross Susan E.; Gore Jonathan S.; Morris Michael L. 《Canadian Metallurgical Quarterly》2003,85(5):933
Examination of the assumptions underlying consistency perspectives in social and personality psychology reveals that they are based on an independent, individualistic view of the self. If the self is constructed as relational or interdependent with others, consistency may be less important in social behavior and well-being. Using a variety of measures of well-being, the studies showed that there is a weaker relation between consistency and well-being for individuals with a highly relational self-construal than for those with a low relational self-construal. Study 3 examined the association between the self-construal, consistency, authenticity, and well-being. These findings reveal the importance of a cultural analysis of theories of the self, personality, and well-being for further theory development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
54.
M Albert C Athanassopoulos LB Auerbach D Bauer R Bolton B Boyd RL Burman I Cohen DO Caldwell BD Dieterle JB Donahue AM Eisner A Fazely FJ Federspiel GT Garvey RM Gunasingha V Highland J Hill R Imlay K Johnston WC Louis A Lu AK Mann J Margulies K McIlhany W Metcalf RA Reeder V Sandberg M Schillaci D Smith I Stancu W Strossman MK Sullivan GJ VanDalen W Vernon YX Wang DH White D Whitehouse D Works Y Xiao S Yellin 《Canadian Metallurgical Quarterly》1995,51(3):R1065-R1069
55.
Utilitarian and economic theories of deterrence hold that the relation of the penalty to the misdeed should be irrelevant. In 5 experiments using hypothetical cases, judgments of penalties depended on whether this relation was in kind (IK) or out of kind (OK). When victims were identifiable, IK penalties were higher than OK and preferred to OK. Subjects seemed to confuse penalties and compensation. When there were no identifiable victims (e.g., environmental damage), IK penalties were preferred, but OK penalties were higher. Here, OK judgments were more uncertain, and subjects preferred to err on the side of overpunishing. The results can be explained in terms of overgeneralization of usually useful heuristics. Alternative hypotheses concerning aggression and scale compatibility are rejected. The findings have implications for the setting of penalties in legal cases (e.g., the Exxon Valdez) and for lay theories of punishment in nonlegal settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
Thomas G. OConnor Jonathan A. Dantzig 《Metallurgical and Materials Transactions B》1994,25(3):443-457
A three-dimensional mathematical model has been developed to compute the thermomechanical state in the mold of thin-slab continuous
casters. The thin-slab mold differs from those used in conventional slab casters in that the upper portion of the broad side
walls defines a funnel-shaped chamber which allows the nozzle to be submerged into the liquid metal. The chamber converges
with distance down the mold, reducing to the rectangular cross section of the finished casting near the mold exit. The new
mold, along with casting speeds up to 6 m/min, allows slabs to be cast 50–60 mm thick, compared with 150 to 350 mm in conventional
continuous slab casting. However, the mold shape and high casting speed lead to higher mold temperatures and shorter mold
life than are found in conventional slab casters. In this article, we develop mathematical models of the process to determine
the role of various process parameters in determining the mold life. Finite-element analysis is used to determine the temperatures
in the mold and cast slab, and these data are then used in an elastic-viscoplastic analysis to investigate the deformation
of the mold wall in service. Cyclic inelastic strains up to 1.75 Pct are found in a region below the meniscus along the funnel
edge. These large strains result from the combination of locally high temperatures coupled with geometric restraint of the
mold. The deformation leads to short mold life because of thermal fatigue cracking of the mold. The computed locations and
time to failure of the mold in fatigue agree very well with observations of the appearance of mold surface cracks in an operating
caster. The models are also used to develop an improved mold design.
Formerly Research Assistant, Department of Mechanical and Industrial Engineering, University of Illinois, Urbana, IL 相似文献
57.
Both Soviet and American youth show a great concern about the possible effects of nuclear war, with heavy media users in both countries more optimistic, but the relation was stronger among Soviet students. 相似文献
58.
The surface-crack-in-flexure (SCF) method uses a Knoop indenter to create small, semielliptical surface precracks in beam specimens. Lateral cracks may interfere with the primary median crack and cause errors of up to 10% in determination of fracture toughness, particularly for materials for which the fracture toughness is ∼3 MPa·m1/2 or less. Although the residual-stress-damage zone is ground or polished away by hand by removing 4.5–5 times the indentation depth, this amount may not be sufficient to completely remove the lateral cracks in low-fracture-toughness materials. A series of tests were conducted on sintered alpha silicon carbide with different amounts of material removed after indentation. Once the lateral cracks were fully removed, the SCF results concurred with single-edged-precracked-beam and chevron-notched-beam data collected in accordance with ASTM Designation C1421. A simple remedy for the SCF method is to examine the outer ground surface for remnants of lateral cracks before fracture and to remove more material if necessary. 相似文献
59.
A sensing strategy for the reverse engineering of machined parts 总被引:1,自引:0,他引:1
The reverse engineering of machined parts requires sensing an existing part and producing a design (and perhaps a manufacturing process) for it. We have developed a reverse engineering system that has proven effective with a set of machined parts. This paper describes the system, presents some results, and discusses strategy for a new system.This work was supported by ARPA under ARO grant number DAAH04-93-G-0420, DARPA grant N00014-91-J-4123, NSF grant CDA 9024721, and a University of Utah Research Committee grant. All opinions, findings, conclusions or recommendations expressed in this document are those of the authors and do not necessarily reflect the views of the sponsoring agencies. 相似文献
60.
The Rules of Beeping: Exchanging Messages Via Intentional "Missed Calls" on Mobile Phones 总被引:1,自引:0,他引:1
Jonathan Donner 《Journal of Computer-Mediated Communication》2007,13(1):1-22
This article explores the practice of "beeping" or "missed calling" between mobile phone users, or calling a number and hanging up before the mobile's owner can pick up the call. Most beeps are requests to call back immediately, but they can also send a pre-negotiated instrumental message such as "pick me up now" or a relational sign, such as "I'm thinking of you." The practice itself is old, with roots in landline behaviors, but it has grown tremendously, particularly in the developing world. Based on interviews with small business owners and university students in Rwanda, the article identifies three kinds of beeps (callback, pre-negotiated instrumental, and relational) and the norms governing their use. It then assesses the significance of the practice using adaptive structuration theory. In concluding, the article contrasts beeping with SMS/text messaging, discusses its implications for increasing access to telecommunications services, and suggests paths for future research. 相似文献